This invention relates to disposable undergarments such as diaper covers, disposable diapers or the like.
Japanese Utility Model Application Gazette No. 1995-7620 discloses a disposable diaper comprising a liquid pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between these two sheets. The topsheet is provided in the middle zone of the crotch region with a liquid-absorbent annular member which is, in turn, covered with a liquid-pervious cover sheet so that the annular member cooperates with a section of the topsheet encircled by the annular member to form an excrement receiving concavity.
Japanese Utility Model Application Disclosure No. 1994-21624 discloses a disposable diaper comprising a liquid pervious topsheet, a liquid-impervious backsheet and an absorbent core disposed between these two sheets. The absorbent core is provided in its hip region with a concavity serving to receive excrement disposed onto the diaper.
Both of the proposals intend to form the absorbent core with a concavity serving to receive solid excretion such as faeces therein with or without a annular protuberance encircling it.
However, various problems may be encountered by such known diapers depending on situations. Assume that the excrement receiving concavity formed in the crotch region or the excrement receiving concavity formed in the hip region misses the proper position to receive the excrement. In this case, the solid excretion can not be received by the concavities.
With the diaper described in Japanese Utility Model Application Disclosure No. 1995-7620, the annular member overlies the absorbent core and increases a thickness of the diaper. The increased thickness of the diaper creates an uncomfortable feeling for the wearer.
In the case of the diaper described in Japanese Utility Model Application Disclosure No. 1994-21624, if the liquid-permeability of the topsheet defining the upper surface of the diaper is not sufficient, the fluid excretion such as loose passage due to diarrhea once having been received by the concavity may flow back again up to the surface of the topsheet and spread sideways.
If the absorbent core is relatively thin as achieved by recent technical progress, it will be difficult to form the concavity adapted to receive a desired amount of excrement.
The above and other objects of the present invention are achieved by a disposable undergarment having along a longitudinal direction thereof a front waist region, a rear waist region and a crotch region therebetween. The undergarment comprises a concavity depressed toward a surface destined to be remote from a wearer""s skin as the undergarment is put on the wearer""s body. The undergarment is made from a panel, which has, in the rear waist region, an afterward bonded edge extending transverse to the longitudinal direction along an end of the panel and being divided by a longitudinal center line of the undergarment into first and second bonded edges. The undergarment is made by bonding the first and second bonded edges of the panel to each other along the longitudinal center line, thereby forming the concavity.
In accordance with one aspect of the present invention, the panel, in the rear waist region, comprises a central portion having the longitudinal center line and first and second wings extending transversely outwardly from opposite sides of the central portion so that the first and second bonded edges of the panel extend continuously from the longitudinal center line into the first and second wings, respectively. Portions of the first and second bonded edges in the first and second wings, respectively, are bonded to each other along the longitudinal center line so as to form the concavity of the undergarment.
In accordance with another aspect of the present invention, the panel is a laminate panel comprising a liquid-pervious topsheet and a liquid-impervious backsheet both extending over the front and rear waist regions as well as the crotch region and the first and second wings, and a liquid-absorbent core disposed between the topsheet and the backsheet.
In accordance with a further aspect of the present invention, the laminate panel further comprises a pair of barrier cuffs extending between transversely opposite side edges of the crotch region and from the front waist region to the rear waist region in the longitudinal direction. The barrier cuffs are biased to rise on an upper surface of the topsheet. Each of the barrier cuffs has a free distal edge being biased away from the upper surface of the topsheet, a proximal edge being bonded to the upper surface of the topsheet, and longitudinally opposite ends respectively lying in the front and rear waist regions. The longitudinally opposite ends of the barrier cuffs which lie in the rear waist region are bonded together along the afterward bonded edge so that the barrier cuffs come in contact with each other in the rear waist region.
In accordance with yet another aspect of the present invention, the longitudinally opposite ends of the barrier cuffs are bonded to the upper surface of the topsheet so that the longitudinally opposite ends are maintained collapsed towards the longitudinal center line of the undergarment.